Overview
The PM6680A, produced by STMicroelectronics, is a dual synchronous step-down controller designed to achieve extremely high efficiency in power conversion. It employs a lossless current sensing technique and a constant on-time architecture, ensuring fast load transient response and nearly constant switching frequency operation. The device features an embedded voltage feed-forward and an integrator control loop to compensate for DC voltage errors due to output ripple. Additionally, it includes a pulse skipping technique to enhance efficiency at light loads and a minimum switching frequency of 33 kHz to avoid audio noise issues.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Input Voltage Range | 6 to 36 | V |
| Output Voltage Range (OUT1) | 0.9 to 5.5 | V |
| Output Voltage Range (OUT2) | 0.9 to 3.3 | V |
| LDO5 Output Voltage | 5 | V |
| LDO5 Peak Current | 100 | mA |
| Reference Voltage | 1.237 ± 1% | V |
| Switching Frequency | Selectable (three different values) | - |
| Minimum Switching Frequency in Pulse Skip Mode | 33 kHz | - |
| Quiescent Power | 5 mW (max) | - |
| Package | VFQFPN-32 (5x5) | - |
| Junction Operating Temperature Range | -40 to 125 | °C |
Key Features
- High efficiency conversion with lossless current sensing technique
- Constant on-time architecture for fast load transient response
- Embedded voltage feed-forward and integrator control loop for output ripple compensation
- Pulse skipping technique for enhanced efficiency at light loads
- Selectable switching frequency and minimum frequency of 33 kHz in pulse skip mode to avoid audio noise
- Soft-start internally fixed at 2ms and soft output discharge
- Latched overvoltage protection (OVP) and undervoltage protection (UVP)
- Independent power good signals for monitoring
- Thermal shutdown protection
- Internal 5V LDO delivering up to 100 mA peak current
Applications
- Embedded computer systems
- FPGA system power
- Industrial applications on 24 V systems
- High-performance and high-density DC/DC modules
Q & A
- What is the input voltage range of the PM6680A?
The input voltage range of the PM6680A is from 6 V to 36 V.
- What are the output voltage ranges for OUT1 and OUT2?
The output voltage range for OUT1 is from 0.9 V to 5.5 V, and for OUT2, it is from 0.9 V to 3.3 V.
- What is the function of the LDO5 in the PM6680A?
The LDO5 is an internal 5V linear regulator that can deliver up to 100 mA peak current.
- How does the pulse skipping mode enhance efficiency?
The pulse skipping mode increases efficiency at very light loads by skipping pulses when the load is low.
- What is the minimum switching frequency in pulse skip mode?
The minimum switching frequency in pulse skip mode is 33 kHz to avoid audio noise issues.
- What are the protection features of the PM6680A?
The PM6680A includes latched overvoltage protection (OVP), undervoltage protection (UVP), and thermal shutdown protection.
- How does the soft-start feature work?
The soft-start is internally fixed at 2ms to ensure a smooth startup.
- What is the purpose of the power good signals?
The power good signals (PGOOD1 and PGOOD2) are used for monitoring purposes, indicating when the output voltages are within their nominal ranges.
- What is the package type of the PM6680A?
The PM6680A is packaged in a VFQFPN-32 (5x5) package.
- What is the junction operating temperature range of the PM6680A?
The junction operating temperature range of the PM6680A is from -40°C to 125°C.
